Reactive dye compounds are known in the art for dyeing various substrates. Such substrates include for example proteinaceous materials such as keratin, e.g. found in hair, skin and nails and various animal body parts such as horns, hooves and feathers, and other naturally occurring protein containing materials, e.g. silk and saccharide-derived materials such as those derived from cellulose or cellulose derivatives, e.g. natural products such as cotton, and synthetic fibres such as polyamides.
Examples of classes of such reactive dyes which are well known in the art include dyes containing a mono- or dichloro- or fluoro- 1,3,5-triazinyl group, trichloro-pyrimidyl or mono-chloro-difluoro pyrimidyl group, alpha,beta-dihalogen-propionyl group, beta-halogenoethyl-sulphonyl group, beta-halogenoethylsulphamyl group, chloroacetyl amino, beta-(chloro-methyl)-beta-sulphatoethylsulphamyl group, or a vinyl sulphonyl, 2,4-dinitro-3,5-difluoroaryl group.
In the case of the dyes containing a triazinyl group or a pyrimidyl group, in place of the reactive halogen atoms one can use other groups which dissociate on reaction with a nucleophile (leaving groups). Canadian Patent 771632, for example, discloses examples of such other groups including sulphonic acid, thiocyanate, sulphophenoxy, sulphophenyl thio, nitrosulphophenoxy groups, and quaternary ammonium groups.
Dyes and Pigments 14, 1990, pages 239-263, “Synthesis and Application of Reactive Dyes with Heterocyclic Reactive Systems” discloses fibre reactive dyes containing monochloro- or dichloro-pyrimidine heterocycle with quaternary ammonium substituents.
There are many different types of reactive dyes for dyeing cellulosic and polyamide-type substrates described in the art. WO9951684, Lewis et al., incorporated herein by reference, discloses reactive dyes comprising a) at least one chromophore moiety, b) at least one nitrogen-containing heterocycle, c) a linking group to link each chromophore moiety to each nitrogen-containing heterocycle characterised in that at least one nitrogen-containing heterocycle is substituted with at least one thio-derivative and at least one quaternized nitrogen derivative. These reactive dyes exhibit increased values of Exhaustion (E) and Fixation (F) compared to previous reactive dyes. A high Exhaustion value for a particular dye compound means that a low level of spent dye remains in the effluent after the dyeing process is complete. The Fixation Value (F) of a reactive dye compound is a measure of the extent of covalent bonding with the substrate based on the dye originally absorbed during the dyeing process.
In addition to these properties, it is also important that the reactive dyes perform well once they have been applied to the textile. The industrial tests commonly used to assess the performance of dyed textiles measure their light fastness, wet and dry crock resistance, dye-transfer staining behavior and wash fastness. In the light fastness test, dyed samples are placed in a sunlight-mimicking unit and irradiated for set amounts of time. The stain test is carried out by attaching to a sample a multifiber test strip. The swatches are run in consumer-mimicking conditions in a washing machine. The test is designed to evaluate any cross staining propensity of dye that might be removed in washing to stain other fibers. The wash fastness test measures the color change on the fabric from the original shade. The sample is washed under consumer-mimicking conditions in a washing machine and the assessment is done visually by a trained (experienced) technician.